Work on the broken "Big Bang" machine will be stepped up
in the new year with the aim of getting the £4 billion atom-smasher
re-started in June.

The Large Hadron Collider suffered a catastrophic
malfunction soon after being switched on amid a fanfare of publicity last
September.

A faulty electrical connection led to a leak of super-cold
helium causing damage estimated at £20 million.

As a result, 53 of the magnets used to accelerate
sub-atomic particles around the machine’s 17-mile underground tunnel have
had to be brought to the surface for repair or cleaning.

Engineers have now designed fail-safe protection systems
to ensure that a similar accident never happens again.

Electronic monitors will provide early warnings of
hazards, and the magnet network will also be fitted with pressure-release
valves to confine the damage caused by any future leak.

The LHC, the biggest atom-smashing machine ever built,
straddles the borders of France and Switzerland and is operated by Cern,
the European particle physics laboratory near Geneva.

It is designed to simulate the "Big Bang", which started
the universe 15 billion years ago, by smashing sub-atomic particles
together at energies never before achieved.

Scientists hope this will help them find the answers to
big questions, such as what causes mass and whether hidden dimensions
exist in space.

There is also a possibility of tiny black holes being
created in the Collider. Experts insist that if this happens, they will
pose no threat.

LHC project leader Lyn Evans said: "We have a lot of work
to do over the coming months, but we now have the roadmap, the time and
the competence necessary to be ready for physics by summer. We are
currently in a scheduled annual shutdown until May, so we’re hopeful that
not too much time will be lost."

The total cost of repairing and refitting the machine is
likely to exceed £30 million.

Scientists hope to have the LHC working again in June, but
its first experiments are not likely to get under way until July.

Liquid helium is used to cool the machine’s magnets to
just 1.8C above absolute zero, nature’s lowest possible temperature. This
allows them to be "superconductors" through which electricity can flow
without resistance.

When the helium leaked and evaporated it caused a number
of the sensitive magnets to warm up and suffer damage.